From Strategy Informer: "There are relatively few commands to memorise when playing Halo Wars, as the interface has clearly been built with accessibility in mind. Selecting all units is mapped to the left bumper while commanding all of your local units is on the right. The A button selects an individual unit whereas holding it down projects a blue area that you can use to paint over as many units as you like. During the early missions, it's entirely possible to get away with manically jabbing LB to select all units before sending the full force of your army into battle and the soldier AI is such that in small skirmishes they can handle themselves perfectly well. However things get much tougher a lot sooner than you'd think, which you'll quickly learn calls for quick thinking and a far more considered strategic approach than simply throwing wave after wave of expendable manpower at a target."